1. Field of the Invention
This invention relates to a method and an apparatus for information processing capable of executing a variety of processing operations for contents data, including e.g. the reproduction of contents data first of all. This invention also relates to a program for execution by such information processing apparatus and to a recording medium having the program stored thereon.
2. Description of Related Art
Recently, an inexpensive hard disc drive (HDD) of a large storage capacity has come into a widespread use. In keeping up therewith, the so-called ripping of recording and saving the audio data, recorded in a medium, such as a CD (Compact Disc), on the hard disc, has become disseminated. This ripping becomes possible by constructing the audio equipment combined from the disc drive capable of reproducing the CD and the HDD. The ripping is also possible with e.g. a personal computer.
Meanwhile, in ripping the sound source of a CD, it is routinely practiced to compress and record audio data in accordance with e.g. the ATRAC (Adaptive Transform Acoustic Coding) system or the MP3 (MPEG-1 Audio layer 3) system.
If audio data, such as a large number of musical numbers, are recorded by ripping on a hard disc as a file, the user may not feel bothered in exchanging and reproducing a CD of an album he/she desires to listen to so that a music listening environment is richer than that attained before.
In the present specification, the file-based AV (audio video) data stored in the recording medium, such as HDD, including the aforementioned audio data first of all, are termed ‘contents data’.
In the contents management application, supervising and reproducing the large number of contents data, recorded on the HDD, the database is routinely used in order to realize efficient management and reproduction of the contents data.
This database is formulated by the contents management information and stored in the HDD.
This database supervises the directories (paths) in the HDD from one contents data to another. A wide variety of the attribute information, including the contents data based titles, artist names or compression formats, first and foremost, are also supervised. There are occasions where relevant data, termed fringe data, typified by the picture data as album jackets or lyric cards, are recorded in conjunction with the contents data. These fringe data are also supervised, such as by showing the paths of the fringe data.
When booting e.g. the contents management application, the information as needed is selected and collected from the database, and the so collected information is utilized to prepare data for contents processing which the contents management application directly exploits for contents management and reproduction. The data for contents processing may be exemplified by list data needed for displaying an overview as a list of the contents registered in the database. Thus, the operation for the contents management operations for such case becomes possible only after the data for contents processing has been completely formulated and the list has been displayed.
The data for contents processing, formulated as described above, is unfolded not on the HDD but on a cache, such as RAM. The contents management application is configured to interpret the data for contents management, thus unfolded on the cache, to execute the list display as described above. That is, if once the data for contents processing is saved in the cache, it is sufficient to access not the database stored in the HDD but the cache area to process the data for contents processing, thus assuring efficient contents management and reproducing operations. As the technique for data read/write, exploiting the cache, there is known such technique disclosed in the Japanese Laying-Open Patent Publication 2002-27419 (Patent Publication 1).
Meanwhile, the cache herein denotes an area on a volatile memory, such as RAM, and has a meaning different from a memory, termed a cache memory, interposed between the CPU and the RAM or the HDD.
However, the processing for filtering and extracting the needed information from the database, in preparing the data for contents processing as described above, is comparatively heavy and time-consuming.
Thus, in the current state of the art, it takes considerable time until the contents management application is completely booted, such as by completion of the list display, to enable the operation. This unduly stresses the user and hence is not desirable. The problem becomes more outstanding in case the number of contents data under management is increased, because the time for formulating the data for contents processing is then protracted.
In an actual system, the data for contents processing is formulated only from the information required for displaying one picture, in connection e.g. with list display, in view of the considerable time needed in formulating the data for contents processing. The data for contents processing is formulated by accessing the database responsive to the scrolling of the list displayed and to the depletion of the data for list display. That is, the processing algorithm currently used is that the data for contents processing which is necessary minimum is prepared from time to time.
With this processing algorithm, in which considerable processing time is needed to prepare each data for contents processing, list display responsive to e.g. scrolling is not smooth, thus again stressing the user.
Moreover, the database is accessed non-periodically responsive to e.g. scrolling, so that other processing, such as reproduction of contents data, executed in real-time, tends to be retarded, thus possibly interfering with stable reproduction of contents data. From the same reason, difficulties may possibly be encountered in achieving stabilized reproduction in need of continuous reproduction between contents data, such as live sound sources, or stabilized special reproduction, such as repeat or random reproduction.
That is, in formulating data for contents processing and for caching under the current state, it takes considerable time to formulate the data for contents processing, so that the time needed since the start of the booting of the contents management application until the operation is enabled is also considerable. Moreover, the risk is high that other processing is impaired in stability.